The invention relates to power mining shovels, such as those used for surface mining. The invention also relates to the splined connection of a rotating shaft and a member that either drives or is driven by the shaft.
A typical power mining shovel includes a revolvable upper frame supported on a mobile carbody. The manner in which the carbody is supported is described below. A fixed boom extends upwardly and outwardly from the frame, and a dipper handle is mounted on the boom for movement for pivotal and translational (non-pivotal) movement relative to the boom. A dipper is fixed to the end of the dipper handle. The outer end of the boom has thereon a sheave, and a hoist cable or rope extends over the sheave and is fastened to the dipper.
The carbody is supported by ground-engaging means, such as crawler track assemblies. A typical crawler track assembly includes a series of shoes that are pivotally pinned together and that have shoe drive lugs which are engaged and pushed by a rotating drive tumbler. The drive tumbler is mounted on a rotating tumbler or drive shaft and has a sprocket-like shape including tumbler lugs that extend radially outward and engage the shoe drive lugs as the tumbler rotates, thereby driving the shoes and moving the crawler track around its endless path. Each crawler track assembly is driven by a motor via a drive train.
U.S. patent application Ser. No. 08/922,838, which was filed Aug. 26, 1997, which is assigned to the assignee hereof, and which is incorporated herein by reference, discloses a disc brake apparatus for such a drive train. The disc brake apparatus includes a brake hub having internal splines engaging external splines on a transmission input shaft. Engagement of the disc brake apparatus prevents rotation of the brake hub which in turn prevents rotation of the input shaft, thereby braking the entire drive train. Obviously, a substantial amount of torque is transmitted by the splines on the brake hub. This can cause these splines to wear out before other components of the drive train.
It is known to "rebuild" the splines by machining the brake hub and providing an insert having thereon new splines. FIG. 1 illustrates a prior art insert 10 in a brake hub 14. The insert 10 has a flange 18 through which screws 22 (only one is shown) and dowels or pins 26 (only one is shown) extend to secure the insert 10 to the hub 14.